1. Technical Field
The present disclosure relates to a light emitting element and a light emitting device using the light emitting element, and a method of manufacturing the same.
2. Description of Related Art
Light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) are generally used in a wide area of applications such as various light sources of backlight or the like, lighting, signaling devices, large-size display devices. Such light emitting elements includes a type in which positive and negative electrodes are arranged on one surface (upper surface) of the light emitting element and a type in which positive and negative electrodes are arranged on different surfaces (upper surface and lower surface) of the light emitting element.
Of those light emitting elements, FIG. 13 to FIG. 20 illustrate the steps of manufacturing a light emitting element 130 that is the type in which the positive and negative electrodes are arranged on one surface. First, as shown in the schematic cross-sectional view of FIG. 13, a semiconductor stacked-layer body is formed stacking an n-type semiconductor layer 131, an active layer 138, and a p-type semiconductor layer 132 in this order on a growth substrate 140 such as a sapphire substrate. Next, as shown in FIG. 14, in order to partially expose the n-type semiconductor layer 131, a portion of the semiconductor stacked-layer body is removed from the upper surface of the p-type semiconductor layer 132 by way of etching or the like.
Next, a light-transmissive electrode such as ITO is disposed. In the present embodiment, as shown in FIG. 15, an ITO layer 139 is formed on approximately entire upper surfaces of the semiconductor stacked layer body. Then, as shown in FIG. 16, a resist film RI is formed on predetermined portions of the upper surface of the ITO layer 139. In this state, etching is carried out to remove the ITO layer 139 from portions other than the predetermined portions of the ITO layer 139 to form an n-side light-transmissive electrode 133 and a p-side light-transmissive electrode 134, as shown in FIG. 17. Then, as shown in FIG. 18, the resist film RI is removed, and as shown in FIG. 19, an n-side pad electrode 135 and a p-side pad electrode 136 are formed. Further, another resist film is disposed and as shown in FIG. 20, a protective film 137 such as SiO2 is formed.
In this method, as shown in FIG. 20, the protective film 137 such as SiO2 remains on the light-transmissive electrodes 133 and 134. Thus, light propagating from the active layer 138 may be hindered by the interfaces between the light transmissive electrodes 133, 134 and the protective film 137, which may result in reduction of the light extraction efficiency. Also, in manufacturing of the light emitting elements, a resist film RI that is used in forming the light-transmissive electrodes 133, 134 and a resist film that is used in forming the protective film 137 are needed to be respectively provided, which complicates manufacturing. See JP 2007-184,597A; and JP 2011-82,589A.
Accordingly, an object of embodiments of the present invention is to provide a light emitting element with further improved light extraction efficiency and simplified manufacturing, and to provide a light emitting device that uses the light emitting element and a method of manufacturing the same.